不同喷油策略对柴油-四氢呋喃混合燃料燃烧和排放的影响

为了解决环境污染和能源短缺等问题，本研究针对四氢呋喃作为一种含氧替代燃料展开研究.在一台六缸增压柴油机上开展了不同喷油策略下四氢呋喃和柴油混合燃料对柴油机燃烧和排放的影响研究，所用3种燃料分别为：纯柴油、5%四氢呋喃和95%柴油、15%四氢呋喃和85%柴油混合燃料（混合比例均为体积比），以原机国六脉谱图为基准调节主喷时刻和喷油压力.结果表明，添加5%四氢呋喃使燃油消耗率增加，有效热效率降低，当加入15%四氢呋喃后燃油消耗率进一步升高，有效热效率相比于添加5%四氢呋喃有一定程度改善，但仍低于纯柴油燃料；当喷油压力高于100 MPa时，混合燃料的燃油消耗率和有效热效率随喷油压力的提高基本保持不变.四氢呋喃加入使小负荷下NO_x、CO和HC排放增加；大负荷下使NO_x排放增加，CO和HC排放逐渐降低，各工况下的碳烟排放均降低.由此可见，柴油-四氢呋喃混合燃料的有效热效率相比于纯柴油降低了1%~2%，加入四氢呋喃可有效降低碳烟排放和改善部分工况下的气体污染物排放.

Effects of different fuel injection strategies on combustion and emissions of diesel-tetrahydrofuran blended fuel

In order to solve the problems of environmental pollution and energy shortage, in this study, the experiment on tetrahydrofuran as an oxygen-containing alternative fuel was performed. A six-cylinder turbocharged diesel engine was used to study the effects of diesel-tetrahydrofuran blended fuel on the combustion and emissions of diesel engines under different injection strategies. The three fuels used were:pure diesel and two different proportions of diesel-tetrahydrofuran blended fuel (the proportions of tetrahydrofuran were 5% and 15% in volume). Main injection timing and injection pressure were adjusted based on the initial MAP up to China VI regulation. The results showed that adding 5% tetrahydrofuran increased the brake specific fuel consumption (BSFC) and reduced the brake thermal efficiency (BTE). When 15% tetrahydrofuran was added, the BSFC was further increased. The BTE was improved to a certain extent compared with adding 5% tetrahydrofuran. When the injection pressure was higher than 100 MPa, the BSFC and BTE of the blended fuels remained basically the same as the injection pressure increased. The addition of tetrahydrofuran increased NO_x, CO, and HC emissions under a low load. The NO_x emissions increased, and the CO and HC emissions gradually decreased under a high load with the addition of tetrahydrofuran. The soot emissions under all operating conditions decreased. It can be seen that the BTE of diesel-tetrahydrofuran blended fuel is 1%~2% lower than that of pure diesel. Diesel-tetrahydrofuran blended fuel can improve soot emissions and air pollutant emissions under some conditions.